1. Implementation 1.Review the mathematical concept. 2.Review the problem solving steps. 3.READ: Children read the part that is asking them to find something out. 4.UNDERSTAND: Children explain what they need to find out. 5.Children identify what information they will need to find it out. 6.Remove the coloured rectangle. 7.Children find the information they need to find it out. 8.CHOOSE A STRATEGY: Children identify strategies that they could use to find it out. 9.USE A STRATEGY: Children use a strategy to find it out. 10.Children record their thinking as they find it out. 11.CHECK: Children reread the part that asked them to find something out. 12.Children check that they have found it out. 13.Children check they have recorded their solution correctly. 14.Children follow the problem solving steps to solve the 2 nd level of the problem, with minimal teacher guidance. 15.Children who solve the 2 nd level, follow the problem solving steps to solve the 3 rd level of the problem independently. 16.Children use the problems as a guide to create their own problem, either alone or in pairs/small groups. 17.Children solve their own problem. Throughout the lesson, children share solution strategies. At the end of the lesson, children explain how they created their own problems.

2. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Lola collected 84 cans. Jill collected 98 cans. How many cans did Lola and Jill collect altogether? Lola collected 38 cans. Jill collected 59 cans. How many cans did Lola and Jill collect altogether? Lola collected 87 cans. Jill collected 76 cans. How many cans did Lola and Jill collect altogether?

3. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Altogether Lola and Jill collected 117 cans. Jill collected 38 cans. How many cans did Lola collect? Altogether Lola and Jill collected 151 cans. Jill collected 41 cans. How many cans did Lola collect? Altogether Lola and Jill collected 139 cans. Jill collected 57 cans. How many cans did Lola collect?

4. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Addition and Subtraction 17

5. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 In a school choir there were 68 boys and 76 girls. How many children? In a school choir there were 53 boys and 48 girls. How many children? In a school choir there were 71 boys and 57 girls. How many children?

6. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Adela added 2 two-digit numbers together and got 147. What might the numbers be? Adela added 2 two-digit numbers together and got 97. What might the numbers be? Adela added 2 two-digit numbers together and got 115. What might the numbers be?

7. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Matt thought of a number. He added 68. The answer was 114. What number did Matt first think of? Matt thought of a number. He added 96. The answer was 173. What number did Matt first think of? Matt thought of a number. He added 14. The answer was 78. What number did Matt first think of?

8. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Jenny showed this number on her calculator. 125 She changed it so that it became this number. 87 What did Jenny do to change 125 to 87? Jenny showed this number on her calculator. 171 She changed it so that it became this number. 99 What did Jenny do to change 171 to 99? Jenny showed this number on her calculator. 101 She changed it so that it became this number. 7 What did Jenny do to change 101 to 7?

9. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 96 + 47 has the same value as 47 + ____ 85 + 73 has the same value as 73 + ____ 52 + 47 has the same value as 47 + ____

10. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 April wrote this correct number sentence. 46 + 78 = 124. Which of these number sentences is also correct? 46 + 124 = 78 78 + 46 = 124 78 + 124 = 46 April wrote this correct number sentence. 36 + 87 =123. Which of these number sentences is also correct? 123 + 36 = 87 87 + 36 = 123 87 + 123 = 36 April wrote this correct number sentence. 59 + 95 = 154. Which of these number sentences is also correct? 95 + 154 = 59 154 - 59 = 95 95 + 95 = 154

11. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 In 67 years, Holly will be 104 years old. How old is Holly now? In 27 years, Holly will be 84 years old. How old is Holly now? In 85 years, Holly will be 109 years old. How old is Holly now?

12. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 38 years ago Holly was 67 years old. How old is Holly now? 18 years ago Holly was 49 years old. How old is Holly now? 26 years ago Holly was 74 years old. How old is Holly now?

13. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Lydia recorded an addition number sentence using 2 two-digit numbers that equalled 145. What could the number sentences have been? Lydia recorded an addition number sentence using 2 two-digit numbers that equalled 116. What could the number sentences have been? Lydia recorded an addition number sentence using 2 two-digit numbers that equalled 99. What could the number sentences have been?

14. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Lydia recorded a subtraction number sentence using a number in the 100s and a two-digit number that equalled 57. What could the number sentences have been? Lydia recorded a subtraction number sentence using a number in the 100s and a two-digit number that equalled 69. What could the number sentences have been? Lydia recorded a subtraction number sentence using a number in the 100s and a two-digit number that equalled 14. What could the number sentences have been?

15. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 I have 78 more apples than oranges. I have 56 oranges. How many apples do I have? I have 101 more apples than oranges. I have 74 oranges. How many apples do I have? I have 98 more apples than oranges. I have 22 oranges. How many apples do I have?

16. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Jenny showed this number on his calculator. 151 She changed it so that it became this number. 82 What did Jenny do to change 151 to 82? Jenny showed this number on his calculator. 117 She changed it so that it became this number. 88 What did Jenny do to change 117 to 88? Jenny showed this number on his calculator. 139 She changed it so that it became this number. 82 What did Jenny do to change 139 to 82?

17. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Matt thought of a number. He subtracted 75. The answer was 58. What number did Matt first think of? Matt thought of a number. He subtracted 98. The answer was 13. What number did Matt first think of? Matt thought of a number. He subtracted 29. The answer was 43. What number did Matt first think of?

18. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 I have 78 fewer apples than oranges. I have 124 oranges. How many apples do I have? I have 18 fewer apples than oranges. I have 116 oranges. How many apples do I have? I have 62 fewer apples than oranges. I have 107 oranges. How many apples do I have?

19. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Betty had 136 shells. She kept 58 and gave the rest to Ben. How many shells did Betty give to Ben? Betty had 118 shells. She kept 33 and gave the rest to Ben. How many shells did Betty give to Ben? Betty had 120 shells. She kept 64 and gave the rest to Ben. How many shells did Betty give to Ben?

20. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 In this room there are 123 chairs. Mary came and took 78 chairs. How many chairs are left? In this room there are 114 chairs. Mary came and took 78 chairs. How many chairs are left? In this room there are 106 chairs. Mary came and took 69 chairs. How many chairs are left?

21. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 In this room there are 87 chairs and next door there are 76 chairs. There 152 children in the grade. Are there enough chairs in the 2 rooms? In this room there are 97 chairs and next door there are 71 chairs. There 170 children in the grade. Are there enough chairs in the 2 rooms? In this room there are 107 chairs and next door there are 65 chairs. There 148 children in the grade. Are there enough chairs in the 2 rooms?

22. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 A car park had 124 spaces. 97 cars were parked. How many spaces were empty? A car park had 104 spaces. 85 cars were parked. How many spaces were empty? A car park had 168 spaces. 97 cars were parked. How many spaces were empty?

23. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Jenny thought of a number. She added 48. Her answer was 127. What number did Jenny think of? Jenny thought of a number. She added 59. Her answer was 116. What number did Jenny think of? Jenny thought of a number. She added 67. Her answer was 133. What number did Jenny think of?

24. Problem Solving Add and Subtract two-digit numbers by partitioning by tens and ones Create your own problem! Now solve it! Addition and Subtraction 17 Johnny thought of a number. He subtracted 48. His answer was 79. What number did Johnny think of? Johnny thought of a number. He subtracted 18. His answer was 99. What number did Johnny think of? Johnny thought of a number. He subtracted 78. His answer was 24. What number did Johnny think of?